Add no-op extras for duckdb and motherduck

Author: treysp

pyproject.toml

@@ -101,9 +101,11 @@ dev = [
 ]
 dbt = ["dbt-core<2"]
 dlt = ["dlt"]
+duckdb = []
 gcppostgres = ["cloud-sql-python-connector[pg8000]>=1.8.0"]
 github = ["PyGithub~=2.5.0"]
 llm = ["langchain", "openai"]
+motherduck = []
 mssql = ["pymssql"]
 mssql-odbc = ["pyodbc"]
 mysql = ["pymysql"]